The US Environmental Protection Agency's Science Advisory Board (SAB) raised fresh questions on Aug. 11 as it completed its peer review of the agency's June 2015 draft of the its study on potential impacts from hydraulic fracturing for oil and gas on drinking water supplies.
It generally found that the agency's approach of focusing on individual stages of hydraulic fracturing water cycle (HFWC) processes for oil and gas's potential impacts on drinking water sources "to be comprehensive but lacking in several critical areas," the board said in its 180-page report to EPA Administrator Gina McCarthy.
It also found that EPA "provided a generally comprehensive overview of the available literature that describes the factors affecting the relationship of hydraulic fracturing and drinking water, and adequately described the findings of such published data in the June 2015 draft assessment report."
The board expressed concerns, however, about various aspects of the draft, including one about several major findings that sought to draw national-level conclusions regarding fracing impacts on drinking water sources.
It found that EPA did not quantitatively support its conclusion about lack of evidence for widespread, systemic impacts of fracing on drinking water resources, and did not clearly describe the system(s) of interest (e.g., groundwater, surface water), the scale of impacts (i.e., local or regional), nor the definitions of "systemic" and "widespread."
It said, "The SAB observes that the statement has been interpreted by readers and members of the public in many different ways. The SAB concludes that if EPA retains this conclusion, [it] should provide quantitative analysis that supports its conclusion that [fracing] has not led to widespread, systemic impacts on drinking water resources."
It recommended that EPA revise major statements of findings in the final report's executive summary and elsewhere in the report to clearly link these statements to evidence provided in the final report's body. It also said EPA should consider prioritizing major findings in Chapters 4-9 according to expectations regarding the magnitude of the potential impacts of fracing-related activities on drinking water resources.
Discuss data limitations
The board also recommended that EPA discuss significant data limitations, as documented in the draft report's body, when presenting the major findings.
"Regarding findings of gaps and uncertainties in publicly available data that the agency relied upon to develop conclusions within the draft assessment report, EPA should clarify and describe the different databases that contain such data and challenges of accessing them, and make recommendations on how these databases could be improved to facilitate more efficient investigation of the data they contain," it said.
"The final assessment report should make clear that while the [fracing] industry is rapidly evolving, with changes in the processes being employed, the assessment necessarily was developed with the data available at a point in time," the board said in its letter.
It also raised questions about recognition of local impacts, prospective case studies, probability and risk of failure scenarios, chemical toxicity and hazards, fracing fluid characteristics, baseline water quality data, water quality and quantity impact assessment approaches, the definition of proximity, fracing wastewater treatment, and best management practices and the applied regulatory framework.
SAB Chairman Peter S. Thorne and SAB Hydraulic Fracturing Research Panel Chairman David A. Dzombak signed the report. Four panel members-Stephen Almond, Shari Dunn-Norman, John Fontana, and Walt Hufford-wrote a dissenting opinion.
Industry groups respond
The American Petroleum Institute and the Petroleum Equipment & Services Association separately responded to SAB's report on Aug. 12.
"The science is clear and the studies are completed," API Upstream and Industry Operations Director Erik Milito said. "Study after study shows that hydraulic fracturing is safe." Its benefits have made the US the world's top oil and gas producer, "and largely due to affordable and abundant supplies of natural gas, we are also leading the world in reducing carbon and other emissions," he said.
EPA's draft assessment report affirms scientific data-including more than 950 sources of information, published papers, numerous technical reports, information from stakeholders, and peer-reviewed EPA scientific reports-showing no widespread, systemic impact from fracing on drinking water quality, Milito said.
He said, "Instead of denying the scientific evidence proving the environmental benefits of [fracing], the US should be celebrating the overwhelming data demonstrating that hydraulic fracturing is helping reduce GHG emissions and other emissions, and has helped lower energy costs for consumers."
PESA Pres. Leslie Beyer, meanwhile, said, "The safe use of [fracing], backed by sound science and bolstered by continuous technology improvements, has provided our nation with significant reductions in [greenhouse gas] emissions and lower energy costs."
EPA's extensive research on tens of thousands of wells across the country concluded that there is no evidence that the process has led to widespread, systemic impacts on US drinking water resources, Beyer said, adding, "Focus on actual science and proven research must drive conclusions."
PESA member companies led the process's development 2 decades ago, and the process has been used on more than 2 million oil and gas wells nationwide, Beyer noted. "The oil field service, supply, and manufacturing sector sees [fracing] as an environmental, economic, and energy security success story that should be embraced as a win for our nation," Beyer said.